The study on the conductivity of styrene-maleic anhydride copolymer electrolytes based on poly(ethylene glycol)400 and LiClO4

Polyelectrolytes, in this study were synthesized from styrene-maleic anhydride (SMA) copolymer, poly(ethylene glycol)400 (PEG400), and lithium perchlorate (LiClO₄). Fourier transform infrared spectroscopy (FTIR), and der="0" style="vertical-align:bottom" width="24" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S001346860400180X-si3.gif"> magic angle spinning (MAS) solid-state NMR were used to monitor the interaction between Li⁺ ions and polymer. The results of FTIR and der="0" style="vertical-align:bottom" width="24" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S001346860400180X-si4.gif"> MAS solid-state NMR indicate the Li⁺ ions are preferentially coordinated to the ether oxygen of PEG. The T_g of the PEG segments in polyelectrolyte increases with LiClO₄ concentration, as determined by differential scanning calorimetry (DSC), indicating that solubility of the Li⁺ ions in the host polymer increases with the PEG content. Impedance spectroscopy (IS) shows that the bulk conductivity of polyelectrolytes and the conductivity behavior obeys the Vogel-Tamman-Fulcher (VTF) equation.     

Synthesis and Characterization of Segmented Block Copolymers Based on Hydroxyl‐Terminated Liquid Natural Rubber and α,ω‐Diisocyanato Telechelics

Summary: Segmented block copolymers, consisting of non‐polar soft segments from hydroxyl‐terminated liquid natural rubber (HTNR) and polar hard segments from α,ω‐diisocyanato telechelics obtained by “criss‐cross”‐cycloaddition, have been synthesized. The block copolymer formation took place under relatively mild reaction conditions at 80 °C in dichloroethane in the presence of dibutyltin dilaurate as a catalyst. The resulting block copolymers were characterized by spectroscopic techniques (¹H NMR, FTIR, UV‐vis spectroscopy) as well as GPC for molar mass determination. The block copolymers were compression molded in a hot stage press, and the resulting samples were characterized by DSC and stress‐strain measurement. The solubility and phase morphology of the materials have also been studied.

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Segmented block copolymer from HTNR and α,ω‐diisocyanato telechelics     

Carbon molecular sieve films produced by dc sputtering

This paper reports adsorption measurements that show molecular sieve effects in amorphous hydrogenated carbon (a-C : H) films deposited by d.c. magnetron discharge decomposition of acetylene. Adsorption of organic gases on the films is studied by using a quartz crystal microbalance technique. The sieve effect in this material depends on both deposition and annealing conditions. Films having significant molecular sieve effects are found to be typically microporous and to have a very small characteristic micropore dimension. It is suggested that the d.c. sputtered a-C : H film may be useful as a molecular sieve material in selective adsorption and gas permeation studies.     

Analysis of epoxidized natural rubber. A comparative study of d.s.c., n.m.r., elemental analysis and direct titration methods

A comparative analysis of epoxidized natural rubber samples by ¹H and ¹³C n.m.r., titrimetric, elemental and d.s.c. techniques has been made. Whereas the titrimetric method is only applicable at low epoxy contents (< 15 mol%) both n.m.r. methods give reasonable precision over the compositional range of 20–75 mol%. Elemental analysis appears less reliable. D.s.c. analysis through measurement of T_g provides the highest precision of measurement but requires independent calibration by one or more of the primary methods. The epoxy content may also be related to the polymer density.     

管窥立体电影反应技术发展

随着电影行业的不断发展,数字3D立体电影的应用日益广泛。本文从立体电影的原理出发,在对传统立体电影的应用技术进行了阐述后,着重分析了现今电影行业应用最为广泛的几种数字3D电影应用技术,集中探讨了不同放映技术的工作原理及其优缺点。最后就数字3D技术的发展前景进行了探讨,为数字3D电影的长远发展提供理论支持。     

Assessment of a redox alkaline/iron-chelate absorption process for the removal of dilute hydrogen sulfide in air emissions

The oxidative absorption of hydrogen sulfide (H₂S) into a solution of ferric chelate of trans-1,2- diaminocyclohexanetetraacetate (CDTA) was studied in a counter-current laboratory column randomly packed with 15 mm plastic Ralu rings. The present investigation takes concern about the Kraft pulping situation where dilute H₂S concentrations are omnipresent in large-volume gas effluents. A fractional two-level factorial approach was instigated to determine the significance of six operating variables, namely the solution's alkalinity (pH; 8.5-10.5), the liquid mass flow rate (L;1.73-der="0" style="vertical-align:bottom" width="115" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si78.gif">), the solution's ionic strength (I_C;0.01-der="0" style="vertical-align:bottom" width="98" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si80.gif">), the gas mass flow rate (G;0.19-der="0" style="vertical-align:bottom" width="116" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si82.gif">), the inlet H₂S concentration (C_H2S,0;70-430 ppm) and the initial ferric CDTA concentration (C_Fe,0;100 -der="0" style="vertical-align:bottom" width="111" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si86.gif">). Initially, a Plackett-Burman design matrix of seven duplicated experiments revealed that pH is the leading factor controlling the H₂S conversion rate while the ionic strength and ferric CDTA concentration effects remained negligible within the factorial domain. Surface response analysis based on 11 duplicated factorial experiments plus 10 central composite trials revealed that the H₂S conversion significantly increases with liquid flow rate but decreases with growing H₂S load up. Further examination about the influence of ferric CDTA on H₂S absorption rate was set up over a broader concentration range (C_Fe,0;0-der="0" style="vertical-align:bottom" width="126" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si92.gif"> at pH of 9.5 and 10.5. It showed good potential at der="0" style="vertical-align:bottom" width="120" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si93.gif"> as H₂S conversion increased by a significant 25% for both pH values in comparison to pure alkaline solutions containing no ferric CDTA.     

平煤四矿丁5,6煤层冲击动力灾害危险区域划分的研究

为了进一步研究和评价矿井冲击地压特征,结合平煤四矿丁5,6煤层阐述了煤岩冲击倾向性测试方法、测试过程及测试结果,根据测试结果在丁5,6煤层中选取了一些特征点,结合开采条件对这些特征点进行赋值,最后运用科学绘图软件绘制了丁5,6冲击动力灾害危险区域划分图,从图中可看出大部分区域为弱冲击倾向,在西翼19160和19180间的窄煤柱区域由于受到两侧采空影响,应力集中很高,具有强冲击倾向,在煤层合并线及煤柱拐角处以及上山煤柱边缘具有中等冲击倾向,为矿井制定有针对性的防治措施提供了参考依据.     

空中预警机三维图像物体检测模型仿真

在当前的空中预警机三维视觉检测中,在进行高空深层视觉检测中,自然环境中会出现大量的检测物,对需要进行三维视觉建模检测的物体形成阴影遮挡干扰.提出了一种新的空中预警机三维图像物体检测方法.把检测过程中遮挡干扰当成一种噪声因素,根据因式分解的相关理论,建立空中预警机三维视觉模型.根据不同遮挡干扰特征点在空中预警机三维视觉建模过程中所占的比率不同,根据非线性滤波原理,设置空中预警机三维视觉对象图像的像素,构建非线性滤波窗口构成的序列,对该空中预警机三维视觉模型进行滤波处理,去除遮挡干扰.实验结果表明,该算法进行空中预警机三维视觉检测,精度达到要求,有一定的实际应用价值.     

虚幻引擎5来临之际游戏专业课程改革与探索

2020年5月,世界著名游戏引擎商家Epic官方揭开了“虚幻引擎5”的神秘面纱。在视频中提到的亿面级数实时渲染“黑科技”更是将这次重大升级提升到了一个前所未有的高度。这次技术的革新之于游戏开发行业的意义可以类比为手机从功能机到智能手机的跃迁。本文笔者将浅谈一些对于游戏引擎的功能介绍,阐述现在游戏引擎对于整个游戏开发行业的重要性,在教学上扩容引擎类软件的学习内容方向和课程安排的一些教学改革思路。     

基于单相机旋转平台的螺纹目标三维重建系统

根据实际检测中方便、快捷、直观的要求,通过CCD相机实时采集旋转平台上螺纹产品信息,通过数学计算进行坐标转换以及三维重建。此方法操作简单,检测精度高,能够检测出螺纹的大径、小径等参数。实验表明,通过标定后,测量的精度达到0．006mm,存在螺纹外观缺陷的产品可100％识别,其过判率小于0．1％。文中详细讲述了系统的构成、检测原理以及上位机软件的数据处理